1. Field of the Invention
The present invention relates to a mobile terminal capable of cancelling composition of the background layer based on the determination that the composition is unnecessary under the display control.
2. Description of the Related Art
Recently, the size of information data supplied to the user at a time has been increasing because of increased size of screen data accompanied with high definition of the display unit (display and the like) of such mobile terminal as the mobile phone. The time taken for the single updating of the screen has been prolonged and the power consumption has been increased owing to the increased screen data size on the display, resulting in deteriorated response to the user's operation and shortened battery life of the mobile terminal.
Japanese Unexamined Patent Application Publication No. 2008-90645 discloses the information processor structured to save the device development cost and a device cost, and further to realize the power saving while improving visual perceptivity of the user. The information processor includes a display unit of a predetermined size, and at least two applications installed therein for outputting display data of a preset size to be displayed on the display unit. The processor further includes a display image data generation unit for generating image data for the display each having the identical size using the respective display data output from the applications, and an image composition output unit for composing the generated image data for the display by superposition so as to be output and displayed on the display unit.
The image on the display of the mobile terminal is generated through composition of plural images (screen layers) The resultant performance is proportional to the number of the screen layers. In the generally employed mobile terminal, it is normally determined whether or not the transmission specification of the screen layer is enabled upon composition of the screen layers. However, it is generally designed to combine the background layer irrespective of the need of the background layer. Accordingly, it is preferable to design the mobile terminal to cancel composition of the background layer which is determined as being unnecessary while preventing the application program at the upper layer from correcting the error.